The North's desire to unify by force is seen in tunnels that have been found. This is an illustration of the 3rd infiltration tunnel. This one is large enough for an invasion force to pass through in an hour. It was indicated on the previous map by the single light.

It was made by blasting through solid granite, 250 feet below ground. A defector from the North helped the South to discover it.

We were not allowed to take our cameras inside the tunnel. It was rough rock finish and was not made for tall people. I had to stoop the whole time I was in it. We went as far as the first of three barriers put in the tunnel.